Pressurized hot water heating system having auxiliary pressurizing vessel



Aug. 24, 1965 G. F. CARLSON PRESSURIZED HOT WATER HEATING SYSTEM HAVIN AUXILIARY PRESSURIZING VESSEL Filed Jan. 25, 1965 ZM ZOE INVENTOR. GIL BE RT F. CARLSON ATTORNEY United States Patent Ofiice 32%,357 Patented Aug. 24, 1965 seem-57 HAVING AUXILIARY PRESSUREZKNG VESSEL Gilbert F. Carlson, Skolde, Iii assignor, by mesne assignments, to International Telephone and Telegraph Corporation, New York, N.Y., a corporation of Maryland i Fiied Jan. 23, 1963, 'Ser. No. 253,441

3 Claims. (Cl. 237.-8)

This invention relates to improvements in hot water systems, and more particularly to systems having an auxiliary pressurized vessel for releasing and receiving quantities of. water to and from the system made necessary by expansion of the system.

Pressurized hot water heating systems present an advantage over vapor systems operating at small gauge pressure in that the heating medium can be maintained at temperatures greatly in excess of 212 F. However, by reason of the expansion in the water in the system, structure mustbe provided for valving off excess water, and upon cooling of the system and contraction of the water, air is introduced into the system with its consequent corrosive effect.

Heretofore inert gases such as nitrogen have been proposed as a pressurizing medium, but its use requires pressure storage vessels and the change in liquid volume as above described requires extensive valving mechanism.

According to the invention herein, pressure is maintained on the system by an auxiliary vessel adapted to receive expanded water from the system or to supply water thereto upon contraction of the water in the system, all the while pressure being maintained on the vessel by an auxiliary steam generator. However, upon rapid return of water to the vessel or rapid release therefrom the pressure on either the suction or discharge sides of the main circulating pump for the system is not maintained Within the nice limits affording desirable system pressures. It is to structure for nicely controlling the system pressure that this invention is directed.

\ One of the principal objects of this invention is to provide a pressurized hot water system characterized by an auxiliary pressurized vessel adapted to receive expanded water from the system, or to return water to the system upon cooling thereof, said auxiliary vessel being controllably connected to either the suction or discharge sides of the main circulating pump so as nicely to control the system pressures.

Another object is to provide in a hot water heating system of the type described, structure for connecting the auxiliary pressure vessel to either the pump discharge or suction side depending on the pressure obtaining in the auxiliary vessel.

Yet another object is to provide valving structure in combination with the main circulating pump, which valving structure is determinative of whether the auxiliary pressure vessel is connected to the suction or discharge sides of said pump.

Other objects and important features of the invention will be apparent from a study of the following specification taken with the drawing, which together describe and illustrate a preferred embodiment of the invention, and what is now considered to be the best mode of practicing the principles thereof. Other embodiments may be suggested to those having the benefit of the teachings herein and such other embodiments are intended to be reserved especially as they fall within the scope and "in volume of liquid in the system thus far described as Referring now to the drawing, the improved hot water heating system embodying the improvements according to the present invention is referred to by thereference numeral 1t), and includes a boiler 11 connected in a pressurized heating system embodying a supply pipe 12 and a return pipe 13. An air separator 14 is connected in the return pipe 13, and a pump 16 in return pipe 13 provides for circulation of heated liquid through the supply and return pipes 12 and 13. H

Apparatus for supplying heat for the boiler is not shown, and the control of such apparatus may be by thermostats or other devices located in areas it is desired to heat. Details of such structure form no part of the present invention and accordingly are not shown herein.

Irrespective of the manner of control of the boiler 11, the areas to be heated comprise radiation elements 1'7 which maybe located in separate areas, these radiation elements 17 being connected in a circuit including the supply and return pipes 12 and 13.

Structure is provided for accommodating the change the liquid is heated, such structureincluding an auxiliary pressurizing vessel 18 connected by a line 19 to a valve 20 selectively connected in turn by lines 20A or 2GB to the return pipe 13 adjacent the intake or outlet side respec tively of said pump for a purpose as will appear.

The auxiliary vessel 18 is adapted to retain a quiescent body of liquid L which varies in volume according to the heat applied to the boiler 11, and tothe circuit comprising the supply and return pipes 12 and 13 and the radiation elements 17. Structure is provided for applying pressure to the volume V above the liquid L within the auxiliary pressurizing tank 18, and includes a small boiler 21 which is heated by a heating element 22. Heating element 22 is energized from any convenient source, and is under the control of a pressure sensing device 23 within vessel 13 and connected by a line 24 back-to the heating element 22 for the control therof.

The level of liquidwithin the boiler 21 is under the control of a float actuated switch 26 connected in a line 27 to control the operation of a pump 28 connected in a line29 connecting the auxiliary tank 18 and theboiler 21. A check valve 31 prevents the flow of liquid from the boiler 21 back to the auxiliary vessel 18. The vapor developed in boiler 21 is connected to volume V within.

vessel 18 by a vapor line 30.

The auxiliary vessel 18 is adapted to be filled from a city Water supply, not shown, but connected thereto by a supply line 32. A fill valve 33 is connected in the supply line 32, and the line 32 is connected to the lower end of the. auxiliary vessel 18 for the filling thereof as well as the heating system previously described.

A fill tank 34 is connected by a supply line 36 branching from the fill line 32. The level of liquid within, the fill tank is controlled by a float operated valve 35.

The level of liquid within the auxiliary pressurizing vessel 18 is controlled by a lower float operated switch 37 connectedin a'power lead 38 to a motor operated pump 39 located in a supply line 41 from the fill tank 34 to the auxiliary press-urizingvessel 18. A check valve 42 is connected in the line ll-between the output of the pump 39 and the vessel 18 to prevent flow in a reverse direction. The float operated switch 37 is adapted to control the energization of the motor operated pump 39 when the level of liquid in the auxiliary tank 18 falls to a certain level. v i A normally closed dump valve 43 operated by a motor 45 is connected in a pipe 44 between the fill tank 34 and the line 32 connected to the lower end of the auxiliary vessel 18. Motor 45 operating valve 43 is under the control of an upper float operated switch 46 connected by a control lead 47 to the motor 45. Thus, when the level of the liquid in the auxiliary vessel 18 rises above a predetermined level, the excess of liquid is dumped at the valve 43, such excess of liquid moving from the auxiliary tank 18 by the line 32 to the line 44 and thence from the dump valve 43.

Pressure within the auxiliary vessel 18 is relieved by a relief valve 48 connected in a pipe 49 leading from the fill tank 34 and to the line 32. Any excess of pressure in the liquid within the auxiliary vessel 18 is thus relieved by the relief valve 48.

Safety meansv are provided for insuring the shut off of the boiler 11 should the lower level in the vessel 18 'be maintained beyond a predetermined time. The float operated switch 37 controlling the admission of new liquid from the fill tank 34 to the auxiliary tank 18 is accordingly connected with a control lead 51 which in turn is connected'to an alarm and boiler shut-off mechanism 52. This mechanism is arranged to cut off the supply of heat to the boiler 11, and to give at the same time an alarm to the operator that the level of liquid within the auxiliary vessel 18 is at too loW a level. However, since the switch 37 is called upon from time to time to control the admission of liquid fnom the fill tank 34 to the auxiliary vessel 18, the operation of the alarm and shut-off 52 does not immediately occur, a suitable delaying mechanism being incorporated in the shut-off mechanism 52, in a manner well known in the art.

Referring back to valve connected between auxiliary vessel 18 and the [return line 13, valve 20 comprises a valve body 50 having spaced webs 53 and 54 providing respectively spaced valve seats 55 and 56. A valve rod 57 is guided in'end Walls 58 and 59 of valve body 50 and has spaced poppets 61 and 62 thereon which close selectively on their proximate seats 55 and 56. The spaced webs 53 and 54 definewith the valve body a chamber 63 to which is connectedline 20A, a second chamber 64 to which is connected the line 19, and a third chamber 66 to which is connected line 2013.

Auxiliary pressure vessel 18 is normally connected to return line 13 through valve 20 either past poppet 61 when unseated,'or' past poppet 62 when it is unseated. Under certain conditions, pressure vessel 18 may be connected to return line past both poppets 61 and 62. The pump 16 is of a type developing a certain increase in pressure head thereacross, and under conditions when a large amount of water returns from the system 11) by expansion via the paths described, a large increase in pressure in vessel 18 can arise by reason of the failure of the vapor in volume to become immediately miscible with the returning liquid. Conversely, when the system water contracts in volume and the pressure drops in vessel 18, too small a working pressure may be developed by pump 16.

The valve rod 57 is accordingly actuated in directions to cause the pressure in vessel 18 to be directed against either the output or input sides of pump 16. Valve rod 57 is connected to a diaphragm 67 held in a diaphragm housing 68. Diaphragm 67 and valve rod 57 are urged in direction to close poppet 62 and open poppet 61 by a spring 69, While diaphragm 67 and valve rod 57 are urged in a direction to open poppet 62 and close poppet 61 by the pressure from the output of pump 16. A line 71' having a hand valve 72 therein accordingly connects the output pressure of pump 16 with diaphragm 67. With valve 20. in the position seen in the drawing, a sudden increase in pressure Within vessel 18 arising by a rapid return of liquid thereto would place the intake of pump 16 under too great a pressure with a consequent undesired output pressure therefrom. Such output pressure would be sensed by diaphragm 67 tomove same to the right to close poppet 61 and open poppet 62 thus relieving the pressure of vessel 18 past valve 20 via line 20A.

Conversely, when the pressure within vessel 18 drops by a sudden contraction of system liquid, the output pressure from pump 16 likewise falls, and diaphragm 67 moves to the left to open poppet 61 and close poppet 62 so that the lower pressure is now placed against the suction side of pump 16.

Alternately, and as shown in the dotted line, the pressure against diaphragm 67 can be that from the intake side of pump 16. If the pressure on the intake side is too high, diaphragm 67 moves to the right, so that the vessel pressure is relieved at the intake side of pump 16. It is believed apparent that between the two extremes of pressure within vessel 18, proper pressure is maintained on the intake and discharge sides of pump 16 by the movement to and fro of the valve rod 57, the valve 20 and the mechanism described forming a pressure bypassing loop.

While the invention has been described in terms of a preferred embodiment thereof, its scope is intended to be limited only by the claims here appended.

I claim:

1. In a closed hot water heating system comprising a boiler and radiation means connected to said boiler in a closed circuit including supply and return lines for said radiation means, a pump for circulating water through said closed circuit, an auxiliary pressurizing vessel including a connection therefrom to said closed circuit, said auxiliary pressurizing vessel being adapted to receive expanded water from said system upon the expansion of water in said system and to return water to said system upon contraction of water in said system, said pressurizing vessel containing the water therein in a normally quiescent fashion undisturbed by circulation in said closed circuit and having means for maintaining the liquid therein under pressure, and valve means in said connection and intermediate said pump and said auxiliary pressurizing vessel for determining Whether said auxiliary pressurizing vessel is connected to the suction or discharge sides of said pump, said valve means including a first connection to the suction side of said pump, a second connection to the discharge side of said pump, a valve actuating member moving in response to pressure conditions at said pump to alternately connect said auxiliary pressure vessel to said first and second connection.

2. In a closed hot water heating system comprising a boiler and radiation means connected to said boiler in a closed circuit including supply and return lines for said radiation means, a pump for circulating water through said closed circuit, an auxiliary pressurizing vessel including a connection therefrom to said closed circuit, said auxiliary pressuri'zing vessel being adapted to re ceive expanded water from said system upon the expansion of Water in said system and to return water to said system upon contraction of water in said system, said pressurizing vessel containing the water therein in a normally quiescent fashion undisturbed by circulation in said closed circuit and having means for maintaining the liquid therein under pressure, and valve means in said connection intermediate said pump and said auxiliary pressurizing vessel for determining Whether said auxiliary pressurizing vessel is connected to the suction or discharge sides of said pump, said valve means including connections to suction and discharge sides of said pump, a valve actuating member including means responsive to the pressure at said pump for moving said valve member, said valve actuating member adopting positions to alternately connect said auxiliary pressure vessel to said first and second connection.

3. In a closed hot water heating system comprising a. boiler and radiation means connected to said boiler in.

a closed circuit including supply and return lines for said.

panded water from said system upon the expansion of water in said system and to return water to said system upon contraction of water in said system, said pressurizing vessel containing the Water therein in a normally quiescent fashion undisturbed by circulation in said closed circuit and having means for maintaining the liquid therein under pressure, and valve means intermediate said pump and said auxiliary pressurizing vessel for determining whether said auxiliary pressurizing vessel is connected to the suction or discharge sides of said pump, said valve including a first connection to the suction side of said pump, a second connection to the discharge side of said pump, a valve actuating member moving to positions to alternately connect said auxiliary pressure vessel through said valve by said first and second connections to correlative sides of said pump, and

means responsive to the pressure at said pump for moving said valve actuating member.

References Cited by the Examiner UNITED STATES PATENTS 1,671,275 5/28 Clithero 23765 X 2,189,941 2/40 Cornell 2378 2,956,553 10/60 Bell.

2,960,272 11/60 Saunders 237-65 3,095,012 6/63 McShane 126-381 FOREIGN PATENTS 186,747 6/07 Germany.

EDWARD J. MICHAEL, Primary Examiner. 

1. IN A CLOSED HOT WATER HEATING SYSTEM COMPRISING A BOILER AND RADIATION MEANS CONNECTED TO SAID BOILER IN A CLOSED CIRCUIT INCLUDING SUPPLY AND RETURN LINES FOR SAID RADIATION MEANS, A PUMP FOR CIRCULATING WATER THROUGH SAID CLOSED CIRCUIT, AN AUXILIARY PRESSURIZING VESSEL INCLUDING A CONNECTION THEREFROM TO SAID CLOSED CIRCUIT, SAID AUXILIARY PRESSURIZING VESSEL BEING ADAPTED TO RECEIVE EXPANDED WATER FROM SAID SYSTEM UPON THE EXPANSION OF WATER IN SAID SYSTEM AND TO RETURN WATER TO SAID SYSTEM UPON CONTRACTION OF WATER IN SAID SYSTEM, SAID PRESSURIZING VESSEL CONTAINING THE WATER THEREIN IN A NORMALLY QUIESCENT FASHION UNDISTURBED BY CIRCULATION IN SAID CLOSED CIRCUIT AND HAVING MEANS FOR MAINTAINING THE LIQUID THEREIN UNDER PRESSURE, AND VALVE MEANS IN SAID CONNECTION AND INTERMEDIATE SAID PUMP AND SAID AUXILIARY PRESSURIZING VESSEL FOR DETERMINING WHETHER SAID AUXILIARY PRESSURIZING VESSEL IS CONNECTED TO THE SUCTION OR DISCHARGE SIDES OF SAID PUMP, SAID VALVE MEANS INCLUDING A FIRST CONNECTION TO THE SUCTION SIDE OF SAID PUMP, A SECOND CONNECTION TO THE DISCHARGE SIDE OF SAID PUMP, A VALVE ACTUATING MEMBER MOVING IN RESPONSE TO PRESSURE CONDITIONS AT SAID PUMP TO ALTERNATELY CONNECT SAID AUXILIARY PRESSURE VESSEL TO SAID FIRST AND SECOND CONNECTION. 